This invention relates generally to equipment used for controlling pollutants contained within gaseous combustion products and relates more particularly to pollutant-controlling combustors used in connection with fireplaces, stoves, and the like.
It is known that in order to control emission levels of various pollutants contained within the gaseous combustion products of fuels burned within a fireplace, stove or other room-heating apparatus or appliance, one or more pollutant-controlling combustors may be mounted adjacent the flue of the apparatus or appliance so that the gaseous combustion products which move toward the flue are routed through the combustors. The combustors include catalysts which, during operation, promote the burning or oxidation of constituents of the combustion products, such as hydrocarbons, which are broadly referred to by the United States Environmental Protection Agency as particulate material. Because of the burning or oxidizing function of the combustors, the effectiveness of the combustors to control pollutants is normally greater at higher operating temperatures than it is at lower operating temperatures.
Each combustor commonly includes a box-like housing having an upstream side through which combustion products enter the combustor and a downstream side through which combustion products exit the combustor. In applications involving a plurality of combustors, the combustors may be arranged in either a series or a parallel flow relationship so that the flow of combustion products may be routed in sequence through all of the combustors or distributed between the combustors before the products are discharged to the atmosphere.
As fuels are burned within a room-heating appliance or apparatus, combustion products are generated more rapidly at higher fuel burn rates than they are at lower burn rates. Consequently, combustor arrangements intended for use at the higher burn rates must accommodate the high volume of combustion products which flow toward the flue. In this connection, environmental regulations have evolved which require a minimum area of combustor surface for handling the combustion products generated at the higher burn rates. However, the pollutant-controlling effectiveness of combustor arrangements intended for use at the higher burn rates is reduced when used at the lower burn rates. Such a reduction in effectiveness is due, at least in part, to the better operating effectiveness of the combustors at higher operating temperatures, which temperatures may not be reached at the lower burn rates.
Accordingly, it is an object of the present invention to provide a new and improved combustor assembly for a fuel-burning room heater having a plurality of combustors of the aforedescribed class and wherein the operating effectiveness of the combustors is enhanced over a broad range of operating temperatures.
Another object of the present invention is to provide such a combustor assembly wherein the operating effectiveness of its combustors is relatively high at both higher and lower fuel burn rates.
Still another object of the present invention is to provide such a combustor assembly which is relatively compact in size and uncomplicated in construction.
Yet another object of the present invention is to provide a firebox/combustor assembly combination which utilizes such a combustor assembly.